memory: make memory_global_sync_dirty_bitmap take an AddressSpace

Since this is a MemoryListener operation, it only makes sense
on an AddressSpace granularity.

Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/memory.c b/memory.c
index 5431463..11bbeb7 100644
--- a/memory.c
+++ b/memory.c
@@ -1485,9 +1485,8 @@
     return ret;
 }
 
-void memory_global_sync_dirty_bitmap(MemoryRegion *address_space)
+void address_space_sync_dirty_bitmap(AddressSpace *as)
 {
-    AddressSpace *as = memory_region_to_address_space(address_space);
     FlatRange *fr;
 
     FOR_EACH_FLAT_RANGE(fr, as->current_map) {